Subcontests
(25)AMC 8 2003 Problem 23 - Cat and Mouse
In the pattern below, the cat (denoted as a large circle in the figures below) moves clockwise through the four squares and the mouse (denoted as a dot in the figures below) moves counterclockwise through the eight exterior segments of the four squares.[asy]defaultpen(linewidth(0.8));
size(350);
path p=unitsquare;
int i;
for(i=0; i<5; i=i+1) {
draw(shift(3i,0)*(p^^shift(1,0)*p^^shift(0,1)*p^^shift(1,1)*p));
}
path cat=Circle((0.5,0.5), 0.3);
draw(shift(0,1)*cat^^shift(4,1)*cat^^shift(7,0)*cat^^shift(9,0)*cat^^shift(12,1)*cat);
dot((1.5,0)^^(5,0.5)^^(8,1.5)^^(10.5,2)^^(12.5,2));label("1", (1,2), N);
label("2", (4,2), N);
label("3", (7,2), N);
label("4", (10,2), N);
label("5", (13,2), N);
[/asy]If the pattern is continued, where would the cat and mouse be after the 247th move?<spanclass=′latex−bold′>(A)</span>
[asy]defaultpen(linewidth(0.8));
size(60);
path p=unitsquare;
int i=0;
draw(shift(3i,0)*(p^^shift(1,0)*p^^shift(0,1)*p^^shift(1,1)*p));
path cat=Circle((0.5,0.5), 0.3);
draw(shift(1,0)*cat);
dot((0,0.5));
[/asy]<spanclass=′latex−bold′>(B)</span>
[asy]defaultpen(linewidth(0.8));
size(60);
path p=unitsquare;
int i=0;
draw(shift(3i,0)*(p^^shift(1,0)*p^^shift(0,1)*p^^shift(1,1)*p));
path cat=Circle((0.5,0.5), 0.3);
draw(shift(1,1)*cat);
dot((0,0.5));
[/asy]<spanclass=′latex−bold′>(C)</span>
[asy]defaultpen(linewidth(0.8));
size(60);
path p=unitsquare;
int i=0;
draw(shift(3i,0)*(p^^shift(1,0)*p^^shift(0,1)*p^^shift(1,1)*p));
path cat=Circle((0.5,0.5), 0.3);
draw(shift(1,0)*cat);
dot((0,1.5));
[/asy]<spanclass=′latex−bold′>(D)</span>
[asy]defaultpen(linewidth(0.8));
size(60);
path p=unitsquare;
int i=0;
draw(shift(3i,0)*(p^^shift(1,0)*p^^shift(0,1)*p^^shift(1,1)*p));
path cat=Circle((0.5,0.5), 0.3);
draw(shift(0,0)*cat);
dot((0,1.5));
[/asy]<spanclass=′latex−bold′>(E)</span>
[asy]defaultpen(linewidth(0.8));
size(60);
path p=unitsquare;
int i=0;
draw(shift(3i,0)*(p^^shift(1,0)*p^^shift(0,1)*p^^shift(1,1)*p));
path cat=Circle((0.5,0.5), 0.3);
draw(shift(0,1)*cat);
dot((1.5,0));
[/asy] AMC 8 2003 Problem 6 - Squares on Triangle Sides
Given the areas of the three squares in the figure, what is the area of the interior triangle?[asy]
real r=22.61986495;
pair A=origin, B=(12,0), C=(12,5);
draw(A--B--C--cycle);
markscalefactor=0.1;
draw(rightanglemark(C, B, A));
draw(scale(12)*shift(0,-1)*unitsquare);
draw(scale(5)*shift(12/5,0)*unitsquare);
draw(scale(13)*rotate(r)*unitsquare);
pair P=shift(0,-1)*(13/sqrt(2) * dir(r+45)), Q=(14.5,1.2), R=(6, -7);
label("169", P, N);
label("25", Q, N);
label("144", R, N);
[/asy]<spanclass=′latex−bold′>(A)</span> 13<spanclass=′latex−bold′>(B)</span> 30<spanclass=′latex−bold′>(C)</span> 60<spanclass=′latex−bold′>(D)</span> 300<spanclass=′latex−bold′>(E)</span> 1800 AMC 8 2003 Problem 10
<spanclass=′latex−bold′>BakeSale</span>
Four friends, Art, Roger, Paul and Trisha, bake cookies, and all cookies have the same thickness. The shapes of the cookies differ, as shown.∘ Art's cookies are trapezoids:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(5,0)--(5,3)--(2,3)--cycle);
draw(rightanglemark((5,3), (5,0), origin));
label("5 in", (2.5,0), S);
label("3 in", (5,1.5), E);
label("3 in", (3.5,3), N);[/asy]∘ Roger's cookies are rectangles:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(4,0)--(4,2)--(0,2)--cycle);
draw(rightanglemark((4,2), (4,0), origin));
draw(rightanglemark((0,2), origin, (4,0)));
label("4 in", (2,0), S);
label("2 in", (4,1), E);[/asy]∘ Paul's cookies are parallelograms:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(3,0)--(2.5,2)--(-0.5,2)--cycle);
draw((2.5,2)--(2.5,0), dashed);
draw(rightanglemark((2.5,2),(2.5,0), origin));
label("3 in", (1.5,0), S);
label("2 in", (2.5,1), W);[/asy]∘ Trisha's cookies are triangles:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(3,0)--(3,4)--cycle);
draw(rightanglemark((3,4),(3,0), origin));
label("3 in", (1.5,0), S);
label("4 in", (3,2), E);[/asy]Each friend uses the same amount of dough, and Art makes exactly 12 cookies. How many cookies will be in one batch of Trisha's cookies?<spanclass=′latex−bold′>(A)</span> 10<spanclass=′latex−bold′>(B)</span> 12<spanclass=′latex−bold′>(C)</span> 16<spanclass=′latex−bold′>(D)</span> 18<spanclass=′latex−bold′>(E)</span> 24 AMC 8 2003 Problem 9
<spanclass=′latex−bold′>BakeSale</span>
Four friends, Art, Roger, Paul and Trisha, bake cookies, and all cookies have the same thickness. The shapes of the cookies differ, as shown.∘ Art's cookies are trapezoids:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(5,0)--(5,3)--(2,3)--cycle);
draw(rightanglemark((5,3), (5,0), origin));
label("5 in", (2.5,0), S);
label("3 in", (5,1.5), E);
label("3 in", (3.5,3), N);[/asy]∘ Roger's cookies are rectangles:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(4,0)--(4,2)--(0,2)--cycle);
draw(rightanglemark((4,2), (4,0), origin));
draw(rightanglemark((0,2), origin, (4,0)));
label("4 in", (2,0), S);
label("2 in", (4,1), E);[/asy]∘ Paul's cookies are parallelograms:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(3,0)--(2.5,2)--(-0.5,2)--cycle);
draw((2.5,2)--(2.5,0), dashed);
draw(rightanglemark((2.5,2),(2.5,0), origin));
label("3 in", (1.5,0), S);
label("2 in", (2.5,1), W);[/asy]∘ Trisha's cookies are triangles:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(3,0)--(3,4)--cycle);
draw(rightanglemark((3,4),(3,0), origin));
label("3 in", (1.5,0), S);
label("4 in", (3,2), E);[/asy]Each friend uses the same amount of dough, and Art makes exactly 12 cookies. Art's cookies sell for 60 cents each. To earn the same amount from a single batch, how much should one of Roger's cookies cost in cents?<spanclass=′latex−bold′>(A)</span> 18<spanclass=′latex−bold′>(B)</span> 25<spanclass=′latex−bold′>(C)</span> 40<spanclass=′latex−bold′>(D)</span> 75<spanclass=′latex−bold′>(E)</span> 90 AMC 8 2003 Problem 8
<spanclass=′latex−bold′>BakeSale</span>
Four friends, Art, Roger, Paul and Trisha, bake cookies, and all cookies have the same thickness. The shapes of the cookies differ, as shown.∘ Art's cookies are trapezoids:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(5,0)--(5,3)--(2,3)--cycle);
draw(rightanglemark((5,3), (5,0), origin));
label("5 in", (2.5,0), S);
label("3 in", (5,1.5), E);
label("3 in", (3.5,3), N);[/asy]∘ Roger's cookies are rectangles:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(4,0)--(4,2)--(0,2)--cycle);
draw(rightanglemark((4,2), (4,0), origin));
draw(rightanglemark((0,2), origin, (4,0)));
label("4 in", (2,0), S);
label("2 in", (4,1), E);[/asy]∘ Paul's cookies are parallelograms:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(3,0)--(2.5,2)--(-0.5,2)--cycle);
draw((2.5,2)--(2.5,0), dashed);
draw(rightanglemark((2.5,2),(2.5,0), origin));
label("3 in", (1.5,0), S);
label("2 in", (2.5,1), W);[/asy]∘ Trisha's cookies are triangles:
[asy]size(80);defaultpen(linewidth(0.8));defaultpen(fontsize(8));
draw(origin--(3,0)--(3,4)--cycle);
draw(rightanglemark((3,4),(3,0), origin));
label("3 in", (1.5,0), S);
label("4 in", (3,2), E);[/asy]Each friend uses the same amount of dough, and Art makes exactly 12 cookies. Who gets the fewest cookies from one batch of cookie dough?<spanclass=′latex−bold′>(A)</span> Art<spanclass=′latex−bold′>(B)</span> Roger<spanclass=′latex−bold′>(C)</span> Paul<spanclass=′latex−bold′>(D)</span> Trisha<spanclass=′latex−bold′>(E)</span> There is a tie for fewest. AMC 8 2003 Problem 24
A ship travels from point A to point B along a semicircular path, centered at Island X. Then it travels along a straight path from B to C. Which of these graphs best shows the ship's distance from Island X as it moves along its course?[asy]size(150);
pair X=origin, A=(-5,0), B=(5,0), C=(0,5);
draw(Arc(X, 5, 180, 360)^^B--C);
dot(X);
label("X", X, NE);
label("C", C, N);
label("B", B, E);
label("A", A, W);[/asy]<spanclass=′latex−bold′>(A)</span>
[asy]
defaultpen(fontsize(7));
size(80);
draw((0,16)--origin--(16,0), linewidth(0.9));
label("distance traveled", (8,0), S);
label(rotate(90)*"distance to X", (0,8), W);
draw(Arc((4,10), 4, 0, 180)^^(8,10)--(16,12));
[/asy]<spanclass=′latex−bold′>(B)</span>
[asy]
defaultpen(fontsize(7));
size(80);
draw((0,16)--origin--(16,0), linewidth(0.9));
label("distance traveled", (8,0), S);
label(rotate(90)*"distance to X", (0,8), W);
draw(Arc((12,10), 4, 180, 360)^^(0,10)--(8,10));
[/asy]<spanclass=′latex−bold′>(C)</span>
[asy]
defaultpen(fontsize(7));
size(80);
draw((0,16)--origin--(16,0), linewidth(0.9));
label("distance traveled", (8,0), S);
label(rotate(90)*"distance to X", (0,8), W);
draw((0,8)--(10,10)--(16,8));
[/asy]<spanclass=′latex−bold′>(D)</span>
[asy]
defaultpen(fontsize(7));
size(80);
draw((0,16)--origin--(16,0), linewidth(0.9));
label("distance traveled", (8,0), S);
label(rotate(90)*"distance to X", (0,8), W);
draw(Arc((12,10), 4, 0, 180)^^(0,10)--(8,10));
[/asy]<spanclass=′latex−bold′>(E)</span>
[asy]
defaultpen(fontsize(7));
size(80);
draw((0,16)--origin--(16,0), linewidth(0.9));
label("distance traveled", (8,0), S);
label(rotate(90)*"distance to X", (0,8), W);
draw((0,6)--(6,6)--(16,10));
[/asy] AMC 8 2003 Problem 25
In the figure, the area of square WXYZ is 25cm2. The four smaller squares have sides 1 cm long, either parallel to or coinciding with the sides of the large square. In ΔABC, AB=AC, and when ΔABC is folded over side BC, point A coincides with O, the center of square WXYZ. What is the area of ΔABC, in square centimeters?[asy]
defaultpen(fontsize(8));
size(225);
pair Z=origin, W=(0,10), X=(10,10), Y=(10,0), O=(5,5), B=(-4,8), C=(-4,2), A=(-13,5);
draw((-4,0)--Y--X--(-4,10)--cycle);
draw((0,-2)--(0,12)--(-2,12)--(-2,8)--B--A--C--(-2,2)--(-2,-2)--cycle);
dot(O);
label("A", A, NW);
label("O", O, NE);
label("B", B, SW);
label("C", C, NW);
label("W",W , NE);
label("X", X, N);
label("Y", Y, N);
label("Z", Z, SE);
[/asy]<spanclass=′latex−bold′>(A)</span> 415<spanclass=′latex−bold′>(B)</span> 421<spanclass=′latex−bold′>(C)</span> 427<spanclass=′latex−bold′>(D)</span> 221<spanclass=′latex−bold′>(E)</span> 227 AMC 8 2003 Problem 22
The following figures are composed of squares and circles. Which figure has a shaded region with largest area?
[asy]/* AMC8 2003 #22 Problem */
size(3inch, 2inch);
unitsize(1cm);
pen outline = black+linewidth(1);
filldraw((0,0)--(2,0)--(2,2)--(0,2)--cycle, mediumgrey, outline);
filldraw(shift(3,0)*((0,0)--(2,0)--(2,2)--(0,2)--cycle), mediumgrey, outline);
filldraw(Circle((7,1), 1), mediumgrey, black+linewidth(1));
filldraw(Circle((1,1), 1), white, outline);
filldraw(Circle((3.5,.5), .5), white, outline);
filldraw(Circle((4.5,.5), .5), white, outline);
filldraw(Circle((3.5,1.5), .5), white, outline);
filldraw(Circle((4.5,1.5), .5), white, outline);
filldraw((6.3,.3)--(7.7,.3)--(7.7,1.7)--(6.3,1.7)--cycle, white, outline);
label("A", (1, 2), N);
label("B", (4, 2), N);
label("C", (7, 2), N);
draw((0,-.5)--(.5,-.5), BeginArrow);
draw((1.5, -.5)--(2, -.5), EndArrow);
label("2 cm", (1, -.5));draw((3,-.5)--(3.5,-.5), BeginArrow);
draw((4.5, -.5)--(5, -.5), EndArrow);
label("2 cm", (4, -.5));draw((6,-.5)--(6.5,-.5), BeginArrow);
draw((7.5, -.5)--(8, -.5), EndArrow);
label("2 cm", (7, -.5));draw((6,1)--(6,-.5), linetype("4 4"));
draw((8,1)--(8,-.5), linetype("4 4"));[/asy]<spanclass=′latex−bold′>(A)</span> A only<spanclass=′latex−bold′>(B)</span> B only<spanclass=′latex−bold′>(C)</span> C only<spanclass=′latex−bold′>(D)</span> both A and B<spanclass=′latex−bold′>(E)</span> all are equal AMC 8 2003 Problem 13
Fourteen white cubes are put together to form the figure on the right. The complete surface of the figure, including the bottom, is painted red. The figure is then separated into individual cubes. How many of the individual cubes have exactly four red faces?[asy]
import three;
defaultpen(linewidth(0.8));
real r=0.5;
currentprojection=orthographic(3/4,8/15,7/15);
draw(unitcube, white, thick(), nolight);
draw(shift(1,0,0)*unitcube, white, thick(), nolight);
draw(shift(2,0,0)*unitcube, white, thick(), nolight);
draw(shift(0,0,1)*unitcube, white, thick(), nolight);
draw(shift(2,0,1)*unitcube, white, thick(), nolight);
draw(shift(0,1,0)*unitcube, white, thick(), nolight);
draw(shift(2,1,0)*unitcube, white, thick(), nolight);
draw(shift(0,2,0)*unitcube, white, thick(), nolight);
draw(shift(2,2,0)*unitcube, white, thick(), nolight);
draw(shift(0,3,0)*unitcube, white, thick(), nolight);
draw(shift(0,3,1)*unitcube, white, thick(), nolight);
draw(shift(1,3,0)*unitcube, white, thick(), nolight);
draw(shift(2,3,0)*unitcube, white, thick(), nolight);
draw(shift(2,3,1)*unitcube, white, thick(), nolight);[/asy]<spanclass=′latex−bold′>(A)</span> 4<spanclass=′latex−bold′>(B)</span> 6<spanclass=′latex−bold′>(C)</span> 8<spanclass=′latex−bold′>(D)</span> 10<spanclass=′latex−bold′>(E)</span> 12 AMC 8 2003 Problem 15
A figure is constructed from unit cubes. Each cube shares at least one face with another cube. What is the minimum number of cubes needed to build a figure with the front and side views shown?[asy]
defaultpen(linewidth(0.8));
path p=unitsquare;
draw(p^^shift(0,1)*p^^shift(1,0)*p);
draw(shift(4,0)*p^^shift(5,0)*p^^shift(5,1)*p);
label("FRONT", (1,0), S);
label("SIDE", (5,0), S);[/asy]<spanclass=′latex−bold′>(A)</span> 3<spanclass=′latex−bold′>(B)</span> 4<spanclass=′latex−bold′>(C)</span> 5<spanclass=′latex−bold′>(D)</span> 6<spanclass=′latex−bold′>(E)</span> 7 AMC 8 2003 Problem 21
The area of trapezoid ABCD is 164cm2. The altitude is 8cm, AB is 10cm, and CD is 17cm. What is BC, in centimeters?
[asy]/* AMC8 2003 #21 Problem */
size(4inch,2inch);
draw((0,0)--(31,0)--(16,8)--(6,8)--cycle);
draw((11,8)--(11,0), linetype("8 4"));
draw((11,1)--(12,1)--(12,0));
label("A", (0,0), SW);
label("D", (31,0), SE);
label("B", (6,8), NW);
label("C", (16,8), NE);
label("10", (3,5), W);
label("8", (11,4), E);
label("17", (22.5,5), E);[/asy]<spanclass=′latex−bold′>(A)</span> 9<spanclass=′latex−bold′>(B)</span> 10<spanclass=′latex−bold′>(C)</span> 12<spanclass=′latex−bold′>(D)</span> 15<spanclass=′latex−bold′>(E)</span> 20 AMC 8 2003 Problem 18
Each of the twenty dots on the graph below represents one of Sarah's classmates. Classmates who are friends are connected with a line segment. For her birthday party, Sarah is inviting only the following: all of her friends and all of those classmates who are friends with at least one of her friends. How many classmates will not be invited to Sarah's party?
[asy]/* AMC8 2003 #18 Problem */
pair a=(102,256), b=(68,131), c=(162,101), d=(134,150);
pair e=(269,105), f=(359,104), g=(303,12), h=(579,211);
pair i=(534, 342), j=(442,432), k=(374,484), l=(278,501);
pair m=(282,411), n=(147,451), o=(103,437), p=(31,373);
pair q=(419,175), r=(462,209), s=(477,288), t=(443,358);
pair oval=(282,303);
draw(l--m--n--cycle);
draw(p--oval);
draw(o--oval);
draw(b--d--oval);
draw(c--d--e--oval);
draw(e--f--g--h--i--j--oval);
draw(k--oval);
draw(q--oval);
draw(s--oval);
draw(r--s--t--oval);
dot(a); dot(b); dot(c); dot(d); dot(e); dot(f); dot(g); dot(h);
dot(i); dot(j); dot(k); dot(l); dot(m); dot(n); dot(o); dot(p);
dot(q); dot(r); dot(s); dot(t);
filldraw(yscale(.5)*Circle((282,606),80),white,black);
label(scale(0.75)*"Sarah", oval);[/asy]<spanclass=′latex−bold′>(A)</span> 1<spanclass=′latex−bold′>(B)</span> 4<spanclass=′latex−bold′>(C)</span> 5<spanclass=′latex−bold′>(D)</span> 6<spanclass=′latex−bold′>(E)</span> 7